@article{DAN_1988_298_2_a6,
     author = {V. L. Rvachev and O. N. Bobyleva},
     title = {Approximation properties of structures of difference type for the},
     journal = {Doklady Akademii Nauk},
     pages = {291--293},
     publisher = {mathdoc},
     volume = {298},
     number = {2},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1988_298_2_a6/}
}